Effective downpipe seal

[Loofah]

My gutter downpipes have little rubber covers where they join the main drain at ground level. These have all popped off so I'm looking to replace or otherwise seal the join somehow. Would these be the best solution? https://www.screwfix.com/p/floplast-rainwater-adaptor-square-65-round-68mm/38593
Or is there a better way? It's 68mm round going to 110mm

 

[JohnD]

Show us some photos of yours please.

Rainwater downpipes have a socket joint enabling them to leak if the pipe is blocked.

 

[Loofah]

No problem -

 

[Loofah]

Would fitting a fully be a better option than the rubber seal I mentioned in first post? This runs to a soak away incidentally

 

[tell80]

Why not lift the down pipe and rubber seal shown in your pic & then measure the diameter (eg 110mm) & post a photo of the ground pipe opening?

AAMOF: rainwater pipes should discharge into gullies, even if the drain runs to a soak away so that any debris can be collected in the gulley trap & cleaned out occasionally.

 

[JohnD]

Would fitting a fully be a better option than the rubber seal I mentioned in first post? This runs to a soak away incidentally

Assuming you mean a gulley

Yes.

 

[Loofah]

Doh. Fat fingers strike again.

Excellent, I'll take a look at what's available. I have noticed in a downpour today that in heavy rain it's backing up so I'll have to have a poke around at some point

 

[JohnD]

With luck you already have a trap, and can fit a grille gulley top. Plastic fittings push together with a rubber ring in the socket

 

[Loofah]

With my builders I very much doubt they put one in but small miracles do happen! Will take a look tomorrow, thanks for the pointers

 

[Loofah]

Have just found a pic from when we had fun and games on another issue and had to dig to go under the house. By luck this is in the exact place so we can see exactly what is installed for my rainwater drain... Downpipe is obvious enough and the pipework somehow runs all the way to the other side of the house into a soakaway. The other is a waste from under the house but that's by the by. The yellow was gas but was removed and an alternate installed elsewhere.

 

[tell80]

What you show is odd.
Why not dig out to where the soakaway drain goes under the house - somewhere along there you could install a trapped gulley and swing the RWP over to discharge into the gulley?
Or you could install an access inspection chamber on the far side of the house?
Or, perhaps you could find a way to install a soakaway in the area of the pic but set back from the house?

 

[Loofah]

My builders made a litany of odd choices.
This has changed a bit from finding a simple cover to wtf have they done with the drains?!
I'll try to post a plan tomorrow, mainly as I've noticed in heavy rain that that rainwater drain backs up which is presumably why the cover keeps popping off

 

[Loofah]

Here we go. I’ve got a shot of the plans and added on the rainwater drainage in blue. As you look at it the ground has a gradual slope which is higher at the soak away point than anywhere else so they must have had to dig very deep to give an adequate slope for water to drain from the front of the house (on the right as you look at the plan) all the way back.
This was a planning condition by the way otherwise we’d have connected to the main sewer a few meters away…

 

[Loofah]

I think it's fair to assume there's no traps fitted. I also think that the pipe run is almost flat so water running away isn't quite quick enough causing a backup in heavy rain. As soon as the rainfall eases it seems to drain ok. Maybe it's a quirk of soakaways or maybe it's a partial block?

Anyway the biggest issue is the overflowing water as due to the location (see pic above) it dribbles back under the house

 

[tell80]

You show roughly a 22m run. and then some - and you say the ground is rising so that the soakaway itself is buried deep.
Given there are no RWP gulley traps then roof/gutter debris will be feeding into that possibly slow moving drainage, & possibly causing blockages well before reaching the soakaway - this will cause heavy rainfall flow to backup and force off the rubber seal?

The remedy, hopefully, would be to fit trapped gullies to all the RWP's & install Inspection Chambers/rodding points at all Tee connections and changes of direction in the soakaway pipe.

This is good practice, necessary anyway but no guarantee if the soakaway itself is inadequate or overwhelmed or the falls begin to rise in the last stretch of drainage - or even that its a badly plumbed installation?
I'm surprised that even partial blockages are occurring in 110mm pipe but the backflow does eventually fall and recede.